This invention relates generally to exercise equipment and more specifically to exercise devices which strengthen the abdominal muscles (the Rectus Abdominous, The Internal and External Obliques and the Transverse Abdominous), and the lower back muscles.
In general, a muscle is strongest at its mid-range of motion. When human beings stand up straight, the muscles of the torso at the center section of the body, which hold the body upright, are in their strongest position, and allow for functional movement bending forward and backward. Most abdominal exercise programs work the abdominal motions from a flat floor. This only brings into play one half of the motion of the muscles, leaving a large weakness in the muscle itself that could develop into numerous back and hip problems.
The abdominal muscles can work or bend the spine over a range from approximately a 30° extension back through center, or the neutral position, to an approximately 25° flexion forward of the neutral position. The function of the abdominal muscles is to bend the spine. The abdominal muscles are in four segments, each of which corresponds to a vertebra on the back. Therefore, when the top abdominal segment contracts, it bends the third and fifth thoracic vertebrae with a pivot point between them. Then when the second abdominal segment contracts, it bends the fifth and sixth thoracic vertebrae and the pivot point moves down between them and so on, until we reach full spinal flexion.
There is a need for an exercise device which exercises the abdominal muscles over their full range of motion, which makes the abdominal muscles work fully, and which exercises the lower abdominal muscle and the lower back muscles as well as the upper abdominal muscles. There also a need to eliminate discomfort and injury to the exerciser due to rubbing and friction occurring at locations of movement and weight-bearing.